4,392 research outputs found

    Predicting User-Interactions on Reddit

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    In order to keep up with the demand of curating the deluge of crowd-sourced content, social media platforms leverage user interaction feedback to make decisions about which content to display, highlight, and hide. User interactions such as likes, votes, clicks, and views are assumed to be a proxy of a content's quality, popularity, or news-worthiness. In this paper we ask: how predictable are the interactions of a user on social media? To answer this question we recorded the clicking, browsing, and voting behavior of 186 Reddit users over a year. We present interesting descriptive statistics about their combined 339,270 interactions, and we find that relatively simple models are able to predict users' individual browse- or vote-interactions with reasonable accuracy.Comment: Presented at ASONAM 201

    Alternative Methods of Increasing the Precision of Weighted Repeat Sales House Prices Indices*

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    Weighted repeat sales house price indices have become one of the primary indicators used to identify housing market conditions and to estimate the amount of equity homeowners have gained through house price appreciation. The primary reason for the acceptance of this methodology is that it derives a location specific (typically, census division, state or metropolitan area) average change in house prices from repeated observations of individual house prices. It is this repeat attribute that allows repeat sales price indices to claim that it is a preferable index which does a better job of holding quality constant. The amount of time between the two observed prices for a single property is determined by when the home transacts. Some homes transact twice in a period of months and others do not transact for decades. It is likely that individual house price appreciation rates vary from the mean appreciation rate, as estimated by the index, in a systematic fashion. In general, the longer the time between transactions the more variance there is in individual house price appreciation. This paper extends this concept to include new dimensions. For instance, houses that appreciate faster than the mean, as estimated by the index for that location, may experience a different variation structure than homes that appreciate slower. This process can be viewed as an asymmetric treatment of the variance of house price appreciation around the estimated index. In addition, the variance of expensive and affordable homes may also be different and time varying. This paper finds evidence that adding the dimensions of price tiers and asymmetry to the variance estimate has merit and does affect the estimated index as well as homeowner equity estimates. Homeowner equity estimates are especially sensitive to these added dimensions because they depend on both the revised index and the estimated variances, which are specific to each dimension considered–time between transaction, asymmetry, and price tier

    Response of Fishes to Revetment Placement

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    Routine fish sampling with hoop nets was conducted monthly from April through December 1978 along natural and revetted riverbanks on the lower Mississippi River near Eudora, Arkansas, to monitor changes in fish populations affected by placement of new revetment for bank protection. Eighteen species of fish were collected with four species comprising over 75% of the total catch. During the months prior to revetment placement, freshwater drum, Aplodinotus grunniens, was the most abundant (32.7% of the catch) species collected. Following in abundance were the flathead catfish, Pylodictis olivaris, (9.8%), common carp, Cyprinus carpio, (7.8%), and blue catfish, Ictalurus furcatus, (3.3%). After revetment placement in August 1978, the freshwater drum was again the most abundant component, comprising 9.7% of the catch. Gizzard shad, Dorosoma cepedianum, flathead catfish, and blue catfish followed in abundance and comprised 8.9, 4.1, and 3.4% of the total catch, respectively. Catch per effort data indicated that fish were generally more abundant at natural bank stations than revetted bank stations but the difference was not significant. The study suggests that fish inhabiting natural riverbank habitat recover quite rapidly from bank perturbation caused by the placement of revetment

    The preparation, identification and properties of chlorophyll derivatives

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    In the investigation of 10-hydroxy chlorophylls a and b novel techniques included modification of chromatography and the use of fully-deuterated compounds isolated from fully-deuterated autotropic algae to determine the molecular structure of the chlorophylls

    Civil and Religious Law in England: A Student\u27s Perspective

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    As a part of a series of lectures on “Islam in English Law,” for the 2008 Temple Festival, the Archbishop of Canterbury, Rowan Williams, gave a lecture titled, “Civil and Religious Law in England: a Religious Perspective.” The lecture referenced Sharia (Muslim divine law) as an example in which the state of England could tease out some of the broader issues around the rights of religious groups within a secular state. Williams intended the lecture to offer a space for serious discussion on what it means to have within society “the presence of communities which, while no less ‘law-abiding’ than the rest of the population, relate to something other than the British legal system alone,” however, many in Britain viewed the lecture as the archbishop’s attempt to implement Sharia in Britain. The misinterpretation of the archbishop’s lecture created an uproar in Britain, which, I thought, highlighted the problem of multiculturalism in the West, particularly, the ignorance that surrounds Islam in the West. The following project examines the archbishop’s lecture, its purpose and misinterpretation, in both its religious and legal dimensions. I argue that beyond sparking discussion on how religious motivation affects law, I thought one of the main points of the lecture was a call for an interfaith, intercultural dialogue to address the ever-changing societal issues of a multicultural state

    Checking the transverse Ward-Takahashi relation at one loop order in 4-dimensions

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    Some time ago Takahashi derived so called {\it transverse} relations relating Green's functions of different orders to complement the well-known Ward-Green-Takahashi identities of gauge theories by considering wedge rather than inner products. These transverse relations have the potential to determine the full fermion-boson vertex in terms of the renormalization functions of the fermion propagator. He & Yu have given an indicative proof at one-loop level in 4-dimensions. However, their construct involves the 4th rank Levi-Civita tensor defined only unambiguously in 4-dimensions exactly where the loop integrals diverge. Consequently, here we explicitly check the proposed transverse Ward-Takahashi relation holds at one loop order in dd-dimensions, with d=4+ϵd=4+\epsilon.Comment: 20 pages, 3 figures This version corrects and clarifies the previous result. This version has been submitted for publicatio

    The γγ\gamma \gamma decay of the f0(1370)f_0(1370) and f2(1270)f_2(1270) resonances in the hidden gauge formalism

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    Using recent results obtained within the hidden gauge formalism for vector mesons, in which the f0(1370)f_0(1370) and f2(1270)f_2(1270) resonances are dynamically generated resonances from the ρρ\rho \rho interaction, we evaluate the radiative decay of these resonances into γγ\gamma \gamma. We obtain results for the width in good agreement with the experimental data for the f2(1270)f_2(1270) state and a width about a factor five smaller for the f0(1370)f_0(1370) resonance, which would agree with preliminary results from the Belle collaboration, hinting at an order of magnitude smaller width for this resonance than for the f2(1270)f_2(1270).Comment: 7 pages, 9 figures, proof of gauge invariance adde

    IMPLEMENTING CONDITION-BASED MAINTENANCE PLUS AS A GROUND MAINTENANCE STRATEGY IN THE MARINE CORPS

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    In 2020, Marine Corps Order 4151.22 and Commandant White Letter 2–20 was published to implement Condition-Based Maintenance Plus (CBM+) as a ground maintenance strategy to improve operational availability and reduce life-cycle costs. The Fleet Marine Force is still operating under preventative and corrective maintenance strategies instead of CBM+ strategies. Organizational inertia, such as competing priorities, legacy processes, and inspections, has slowed the integration of CBM+ strategies. We reviewed key policy documents and interviewed fifteen subject-matter experts relevant to Marine Corps ground transport maintenance policies and practices. Based on this information, we conducted a thematic analysis using an organizational change approach to identify barriers and opportunities that impact CBM+ implementation. We found that immediate gains from CBM+ implementation in the Marine Corps can be achieved through a focus on people and process improvements while technology integration continues. The CBM+ strategy supports Force Design 2030 and Talent Management 2030 objectives and emphasizing this alignment can build momentum for CBM+. In this paper, we make six specific recommendations that apply organizational change concepts to enable effective CBM+ implementation as a ground maintenance strategy in the Marine Corps.NPS Naval Research ProgramThis project was funded in part by the NPS Naval Research Program.Major, United States Marine CorpsMajor, United States Marine CorpsApproved for public release. Distribution is unlimited
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